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Rebuilt from sources: board is 820-0327-A with 17 SMD electrolytics (10x10uF/5x47uF/1x100uF/1x1uF) - the previous C1-C17 table was wrong and was NOT identical to the LC. Designators from Console5, totals corroborated by Recap-a-Mac. Procedure/PSU now cross-referenced to the LC page; refs added; {{Unverified data}} cleared
 
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{{Unverified data}}
Replacing the surface-mount electrolytic capacitors in the '''Macintosh LC II''' is
Replacing the electrolytic capacitors (recapping) in the '''Macintosh LC II''' is essential for long-term reliability. The original capacitors used in these machines are now over 30 years old and commonly leak, causing corrosion and circuit damage.
essential maintenance. The 1991-vintage SMD electrolytics leak, and the electrolyte attacks the solder
mask and the copper beneath it.


== Symptoms of Capacitor Failure ==
The LC II logic board is '''820-0327-A''', a different board from the original LC with a different
capacitor complement, so the two lists are not interchangeable. The same board is used by the
[[Macintosh Performa 400|Performa 400]], 405, 410 and 430.<ref name="ss-p400">Apple Computer, ''Service Source: Macintosh Performa 400 Series'' — covers the Performa 400/405, 410, 430, 450, 460/466/467 and 475/476. Hosted on this wiki as [[:File:Performa 400 series.pdf]]; see [[Macintosh Performa 400 Series Service Source]].</ref>


* '''No audio''' — Most common early symptom
The tools, the removal and fitting procedure, the power supply data and the battery information are
* '''Distorted or crackling audio'''
common to the whole "pizza box" family and are documented once, on the
* '''Boot failures or instability'''
[[Macintosh LC Capacitor Replacement Guide]]. This page carries only what is specific to the LC II.
* '''Visible electrolyte leakage''' — Brown or black residue around capacitors
* '''Corrosion on PCB traces'''


== Capacitor List ==
== Symptoms of capacitor failure ==


=== Logic Board Capacitors ===
The pattern is the same as the rest of the family: sound goes first, then intermittent starting, then
visible residue and corroded copper. Because the −5 V rail on these boards exists mainly to feed
the RS-422 serial drivers, a failed bulk capacitor on that rail tends to show up as modem and printer
port trouble on its own.<ref name="ddb">Doug Brown, [https://www.downtowndougbrown.com/2024/11/the-capacitor-that-apple-soldered-incorrectly-at-the-factory/ “The capacitor that Apple soldered incorrectly at the factory”], 26 November 2024. Continuity and voltage measurements showing that C22 on the LC III board has its positive terminal on −5 V and its negative terminal on ground; comparison with the LC, LC II and LC 475 boards, which are wired the other way round; and the reported consequences of fitting a tantalum in the silkscreened orientation.</ref> See
[[Macintosh LC Capacitor Replacement Guide]] for the full symptom list, and
[[Capacitor Failure Symptoms]] for the general picture.


The Macintosh LC II logic board contains 17 surface-mount electrolytic capacitors, identical in specification to the original LC.
== Macintosh LC II logic board (820-0327-A) ==


{| class="wikitable" style="width:80%; text-align:center;"
Seventeen surface-mount electrolytic capacitors. The per-designator list is Console5's; the totals by
|+ '''Macintosh LC II Logic Board Capacitors'''
value — ten 10 µF, five 47 µF, one 100 µF and one 1 µF —
|-
match the independently produced Recap-a-Mac photograph of the same board exactly.<ref name="console5-lc">[https://wiki.console5.com/wiki/Macintosh_LC Console5 Wiki — Macintosh LC]. Community-maintained capacitor lists giving per-designator values for logic boards 630-0309 (LC), 820-0327-A (LC II) and 820-0650-A/B (LC III), and for six different LC-family power supplies. Secondary source: not an Apple document, but it agrees value-for-value with the independent Recap-a-Mac photographs.</ref><ref name="ram-lcii">[https://recapamac.com.au/macintosh-lcii/ Recap-a-Mac — Macintosh LC II (Performa 400)]. Annotated photograph of the 820-0327 logic board. Hosted on this wiki as [[:File:Mac LC II Recap Guide.jpg]]. Secondary source.</ref>
! Designator !! Capacitance !! Voltage !! Type
 
|-
<templatestyles src="Template:StyledTable/styles.css" />
| C1 || 1 µF || 50V || SMD Electrolytic
{| class="wikitable styled-table" style="width:70%; text-align:center;"
|-
|+ Macintosh LC II logic board 820-0327-A — SMD electrolytics
| C2 || 1 µF || 50V || SMD Electrolytic
! Designator !! Value !! Working voltage
|-
|-
| C3 || 10 µF || 16V || SMD Electrolytic
| C11, C12, C14, C15, C16, C17, C18, C21, C97, C139 || 10 µF || 16 V
|-
|-
| C4 || 10 µF || 16V || SMD Electrolytic
| C2, C3, C4, C13, C19 || 47 µF || 16 V
|-
|-
| C5 || 10 µF || 16V || SMD Electrolytic
| C10 || 100 µF || 6.3 V
|-
|-
| C6 || 10 µF || 16V || SMD Electrolytic
| C22 || 1 µF || 50 V
|-
| C7 || 47 µF || 16V || SMD Electrolytic
|-
| C8 || 47 µF || 16V || SMD Electrolytic
|-
| C9 || 47 µF || 16V || SMD Electrolytic
|-
| C10 || 47 µF || 16V || SMD Electrolytic
|-
| C11 || 47 µF || 16V || SMD Electrolytic
|-
| C12 || 47 µF || 16V || SMD Electrolytic
|-
| C13 || 47 µF || 16V || SMD Electrolytic
|-
| C14 || 47 µF || 16V || SMD Electrolytic
|-
| C15 || 100 µF || 6.3V || SMD Electrolytic
|-
| C16 || 100 µF || 6.3V || SMD Electrolytic
|-
| C17 || 100 µF || 6.3V || SMD Electrolytic
|}
|}


[[File:Mac LC II Recap Guide.jpg|center|thumb|600px|Macintosh LC II logic board capacitor locations. Source: [https://recapamac.com.au/macintosh-lcii/ Recap-a-Mac]]]
'''Note on C22.''' The LC III has a well-known reversed capacitor at C22. The LC II also has a C22, but
 
it is a different part in a different place — a 1 µF 50 V — and there is nothing
=== Power Supply Capacitors ===
wrong with it. The LC and LC II bulk capacitors on the −5 V rail are wired the correct way
 
round; only the LC III board is affected.<ref name="ddb" />
The LC II uses the same power supply as the original LC. Refer to the [[Macintosh LC Power Supply Recap Guide]] for PSU-specific information.


[[File:Mac LC PSU Recap Guide.jpg|center|thumb|600px|Macintosh LC power supply capacitor locations. Source: [https://recapamac.com.au/macintosh-lc-power-supply/ Recap-a-Mac]]]
[[File:Mac LC II Recap Guide.jpg|center|thumb|700px|Macintosh LC II logic board 820-0327 with every
electrolytic marked with its value, working voltage and positive terminal. Source: Recap-a-Mac.]]


== Capacitor Replacement Procedure ==
== Power supply, battery and procedure ==


=== Tools Required ===
Identical to the rest of the family, and documented on
[[Macintosh LC Capacitor Replacement Guide]]: Apple power supply '''661-1733''' (universal
100–240 VAC, six known vendor variants with different capacitor complements) and lithium battery
'''742-0011''', which Apple says to replace below 3.0 V.<ref name="ss-lc">Apple Computer, ''Service Source: Macintosh LC Series / Quadra 605'' — Specifications, Troubleshooting, Take Apart, Additional Procedures and Exploded View chapters. Hosted on this wiki as [[:File:Quadra 605.lc series.pdf]]; see [[Macintosh LC Series/ Quadra 605 Service Source]].</ref><ref name="ss-p400" />


* Temperature-controlled soldering iron (recommended: 300-350°C)
== Things that are not faults ==
* Fine tip for SMD work
* Desoldering braid or solder wick
* Flux (no-clean recommended)
* Isopropyl alcohol (99%)
* Soft brush (ESD-safe)
* Multimeter
* Replacement SMD electrolytic capacitors


=== Procedure ===
* '''No FPU socket.''' The LC II uses a 68030, which has no on-chip FPU, and Apple did not fit a
  coprocessor socket to this board — the socket first appears on the LC III.<ref name="ss-lc" /> Software that
  demands an FPU will not run, and that is not a capacitor problem.
* '''10 MB RAM ceiling.''' You can install 12 MB but the machine only addresses 10 MB. Apple
  documents this explicitly.<ref name="ss-lc" />
* '''Mono sound.''' Apple's specification for the LC, LC II and LC III is a monophonic 8-bit sound
  generator feeding the same signal to both channels.<ref name="ss-lc" />


# '''Remove the logic board''' — Disconnect all cables, remove screws, and carefully lift the board.
== Related pages ==
# '''Document capacitor positions''' — Note polarity markings before removal.
# '''Clean the area''' — Remove any leaked electrolyte with isopropyl alcohol.
# '''Remove old capacitors''' — Heat one pad while gently lifting the capacitor. Alternate between pads. Use flux to help solder flow.
# '''Clean the pads''' — Remove old solder with desoldering braid. Clean with IPA.
# '''Inspect for damage''' — Check traces and vias for corrosion. Repair any damaged traces.
# '''Install new capacitors''' — Observe polarity. The stripe on the capacitor indicates negative. Tin one pad, position capacitor, solder second pad, reflow first pad.
# '''Clean residue''' — Remove flux with isopropyl alcohol.
# '''Test continuity''' — Verify no shorts between +5V, +12V, and ground.
# '''Reassemble and test''' — Listen for the startup chime, verify video, and check audio output.
 
== Important Notes ==
 
* '''Polarity matters''' — SMD electrolytics will fail if installed backwards.
* '''Use equivalent or better specs''' — Match capacitance; voltage rating can be equal or higher.
* '''Low-ESR capacitors''' — Modern low-ESR replacements are acceptable.
* '''No FPU socket''' — Note that the LC II does not have an FPU socket on the logic board, despite the 68030's FPU support.
 
== Related Pages ==


* [[Macintosh LC II]]
* [[Macintosh LC II]]
* [[Macintosh LC II General Maintenance]]
* [[Macintosh LC II General Maintenance]]
* [[Macintosh LC II Troubleshooting]]
* [[Macintosh LC II Troubleshooting]]
* [[Macintosh LC Capacitor Replacement Guide]] — shared procedure, power supply and battery
* [[Macintosh LC Series/ Quadra 605 Service Source]]


== External Resources ==
== References ==
 
<references />
* [https://recapamac.com.au/macintosh-lcii/ Recap-a-Mac: Macintosh LC II Capacitor Guide]


[[Category:Apple Vintage Computers]]
[[Category:Apple Vintage Computers]]
[[Category: Capacitor Replacement Guides]]
[[Category:Capacitor Replacement Guides]]
{{Navbox-AppleVintage|state=collapsed}}

Latest revision as of 00:41, 23 September 2026

Replacing the surface-mount electrolytic capacitors in the Macintosh LC II is essential maintenance. The 1991-vintage SMD electrolytics leak, and the electrolyte attacks the solder mask and the copper beneath it.

The LC II logic board is 820-0327-A, a different board from the original LC with a different capacitor complement, so the two lists are not interchangeable. The same board is used by the Performa 400, 405, 410 and 430.[1]

The tools, the removal and fitting procedure, the power supply data and the battery information are common to the whole "pizza box" family and are documented once, on the Macintosh LC Capacitor Replacement Guide. This page carries only what is specific to the LC II.

Symptoms of capacitor failure

[edit | edit source]

The pattern is the same as the rest of the family: sound goes first, then intermittent starting, then visible residue and corroded copper. Because the −5 V rail on these boards exists mainly to feed the RS-422 serial drivers, a failed bulk capacitor on that rail tends to show up as modem and printer port trouble on its own.[2] See Macintosh LC Capacitor Replacement Guide for the full symptom list, and Capacitor Failure Symptoms for the general picture.

Macintosh LC II logic board (820-0327-A)

[edit | edit source]

Seventeen surface-mount electrolytic capacitors. The per-designator list is Console5's; the totals by value — ten 10 µF, five 47 µF, one 100 µF and one 1 µF — match the independently produced Recap-a-Mac photograph of the same board exactly.[3][4]

Macintosh LC II logic board 820-0327-A — SMD electrolytics
Designator Value Working voltage
C11, C12, C14, C15, C16, C17, C18, C21, C97, C139 10 µF 16 V
C2, C3, C4, C13, C19 47 µF 16 V
C10 100 µF 6.3 V
C22 1 µF 50 V

Note on C22. The LC III has a well-known reversed capacitor at C22. The LC II also has a C22, but it is a different part in a different place — a 1 µF 50 V — and there is nothing wrong with it. The LC and LC II bulk capacitors on the −5 V rail are wired the correct way round; only the LC III board is affected.[2]

Macintosh LC II logic board 820-0327 with every electrolytic marked with its value, working voltage and positive terminal. Source: Recap-a-Mac.

Power supply, battery and procedure

[edit | edit source]

Identical to the rest of the family, and documented on Macintosh LC Capacitor Replacement Guide: Apple power supply 661-1733 (universal 100–240 VAC, six known vendor variants with different capacitor complements) and lithium battery 742-0011, which Apple says to replace below 3.0 V.[5][1]

Things that are not faults

[edit | edit source]
  • No FPU socket. The LC II uses a 68030, which has no on-chip FPU, and Apple did not fit a
 coprocessor socket to this board — the socket first appears on the LC III.[5] Software that
 demands an FPU will not run, and that is not a capacitor problem.
  • 10 MB RAM ceiling. You can install 12 MB but the machine only addresses 10 MB. Apple
 documents this explicitly.[5]
  • Mono sound. Apple's specification for the LC, LC II and LC III is a monophonic 8-bit sound
 generator feeding the same signal to both channels.[5]
[edit | edit source]

References

[edit | edit source]
  1. ↑ 1.0 1.1 Apple Computer, Service Source: Macintosh Performa 400 Series — covers the Performa 400/405, 410, 430, 450, 460/466/467 and 475/476. Hosted on this wiki as File:Performa 400 series.pdf; see Macintosh Performa 400 Series Service Source.
  2. ↑ 2.0 2.1 Doug Brown, “The capacitor that Apple soldered incorrectly at the factory”, 26 November 2024. Continuity and voltage measurements showing that C22 on the LC III board has its positive terminal on −5 V and its negative terminal on ground; comparison with the LC, LC II and LC 475 boards, which are wired the other way round; and the reported consequences of fitting a tantalum in the silkscreened orientation.
  3. ↑ Console5 Wiki — Macintosh LC. Community-maintained capacitor lists giving per-designator values for logic boards 630-0309 (LC), 820-0327-A (LC II) and 820-0650-A/B (LC III), and for six different LC-family power supplies. Secondary source: not an Apple document, but it agrees value-for-value with the independent Recap-a-Mac photographs.
  4. ↑ Recap-a-Mac — Macintosh LC II (Performa 400). Annotated photograph of the 820-0327 logic board. Hosted on this wiki as File:Mac LC II Recap Guide.jpg. Secondary source.
  5. ↑ 5.0 5.1 5.2 5.3 Apple Computer, Service Source: Macintosh LC Series / Quadra 605 — Specifications, Troubleshooting, Take Apart, Additional Procedures and Exploded View chapters. Hosted on this wiki as File:Quadra 605.lc series.pdf; see Macintosh LC Series/ Quadra 605 Service Source.
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